Also:
-) use matray: setup it to notify you at least about Stable updates;
-) better to update not in GUI, but in text terminal - you can see a lot of info there, sometimes you can see more valuable descriptions of events there and it is easier to copy the suspected event text from it. Also useful to copy several lines in order to show the event sequence to you and other readers if you post it;
-) read the update output in order to get rid of *.pacnew files directly after each update Why integrate .pacnew files?
-) do not be in a hurry to reboot if you saw suspicious warnings. May be it will be harder to recover, cause need to load liveCD environment. Search it may be someone already reported it earlier and if you can’t recognize the event and it’s severity, post it;
-) as was said earlier: always have manjaro livecd. Update the images list there from time to time and have a 2-3 recent image versions just in case if most recent one will fail (ventoy can help you to store several images of any type with your user data on the same storage).
-) after an image download before to burn image/copy image to a drive check a hash sum (currntly of sha-X types) to make you sure that the image was not corrupted between creation moment and the moment of making your copy (during storing on server, downloading, your hardware usage).
-) in case of hard failures for example of a hardware, better to do a backups.
And… constant/lifetime task:
from time to time learn something new about instruments you use: that makes you more powerful user after each case learned, a person, who can solve problems easier, faster and even to improve a packages by having and using abilities to properly (fully, precise, with good debug data) report of a package issues. That will brings more comfort while app usage to you and any other user.